- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄359234 > MT90520 (Zarlink Semiconductor Inc.) 8-Port Primary Rate Circuit Emulation AAL1 SAR PDF資料下載
參數(shù)資料
| 型號： | MT90520 |
| 廠商： | Zarlink Semiconductor Inc. |
| 英文描述： | 8-Port Primary Rate Circuit Emulation AAL1 SAR |
| 中文描述： | 8端口基本速率電路仿真AAL1特區(qū) |
| 文件頁數(shù)： | 80/180頁 |
| 文件大小： | 1736K |
| 代理商： | MT90520 |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁第49頁第50頁第51頁第52頁第53頁第54頁第55頁第56頁第57頁第58頁第59頁第60頁第61頁第62頁第63頁第64頁第65頁第66頁第67頁第68頁第69頁第70頁第71頁第72頁第73頁第74頁第75頁第76頁第77頁第78頁第79頁當前第80頁第81頁第82頁第83頁第84頁第85頁第86頁第87頁第88頁第89頁第90頁第91頁第92頁第93頁第94頁第95頁第96頁第97頁第98頁第99頁第100頁第101頁第102頁第103頁第104頁第105頁第106頁第107頁第108頁第109頁第110頁第111頁第112頁第113頁第114頁第115頁第116頁第117頁第118頁第119頁第120頁第121頁第122頁第123頁第124頁第125頁第126頁第127頁第128頁第129頁第130頁第131頁第132頁第133頁第134頁第135頁第136頁第137頁第138頁第139頁第140頁第141頁第142頁第143頁第144頁第145頁第146頁第147頁第148頁第149頁第150頁第151頁第152頁第153頁第154頁第155頁第156頁第157頁第158頁第159頁第160頁第161頁第162頁第163頁第164頁第165頁第166頁第167頁第168頁第169頁第170頁第171頁第172頁第173頁第174頁第175頁第176頁第177頁第178頁第179頁第180頁
MT90520
Data Sheet
80
Zarlink Semiconductor Inc.
As in the UDT RX_SAR, the SDT RX_SAR is responsible for compensating for sequence number error conditions.
Up to 6 dummy cells may be inserted into the various SDT Reassembly Circular Buffers corresponding to the VC in
question.
The SDT RX_SAR compares the value of the SDT RX_SAR’s write pointer and the TDM module’s read pointer,
prior to the transfer of each cell to the SDT Reassembly Circular Buffers. The result of the comparison determines
whether a slip-error needs to be reported in the MIB statistics, and may also result in an adjustment of the write
pointer’s location before a cell is written to the SDT Reassembly Circular Buffers (see “SDT Overflow and Underrun
Detection” on page 84).
Pointer Processing
Within SDT-formatted cells, pointers are used to indicate the location of the first channel of data within an AAL1
structure.
A pointer can be received only from an even-numbered cell which is identified as a pointer-type cell because its CSI
bit is set. Pointers are received in this manner for all SDT VCs, except for non-CAS cells carrying one channel. In
that special case, no pointers should be received.
Once an even-numbered cell with a set CSI bit is received, the pointer byte of the cell is processed. First, some
error-checking procedures are performed:
the pointer byte is examined for even-parity errors. If there is a parity error, the contents of the pointer byte
are ignored, the
Pointer Parity Errors
MIB statistic field in the SDT Reassembly Control Structure is
incremented, and the pointer-processing routine is exited.
if no parity error is found, the 7 least-significant bits of the pointer byte (the 8-bit pointer byte, less the parity
bit) are then examined to see if they exceed the maximum allowable “valid” pointer value of 93d (5Dh). If
either of the following cases is true, the pointer processing routine is exited:
if the pointer byte has a value of 127d (7Fh), it is a “dummy” pointer (a valid pointer value); this pointer
value is ignored by the SDT RX_SAR.
if the pointer byte has a value exceeding 93d and does not equal 127d, it is an illegal pointer value;
therefore, the pointer value is ignored and a Pointer_Out_of_Range error is detected, causing the
Po
status bit of the SDT Reassembly Control Structure for the VC to be set.
If the above error conditions are not met, the pointer byte is considered to be valid and is processed as such by the
SDT RX_SAR:
the pointer byte is automatically considered to be correct (based on the fact that there is a lot of
protection on the AAL1 byte, so bytes should not be received marked erroneously as pointers).
Therefore, the “golden” received pointer value is always used to determine where the SDT RX_SAR
should currently be operating within a VC’s AAL1 structure. Regardless of where the SDT RX_SAR is
pointing in the AAL1 structure, it is adjusted to point to the location identified by the received pointer byte.
-
if the received pointer matches the SDT RX_SAR’s internal location controller, all is well and no errors
are reported.
-
if the internal location controller doesn’t match the received pointer, a framing/data misalignment error
has occurred:
- if the received pointer is equal to 0, the pointer misalignment is corrected immediately;
therefore, the
Pointer Reframes
statistic field in the SDT Reassembly Control Structure
is incremented.
- if the received pointer is not equal to 0, the misalignment between the internal
controller and the received pointer is not resolved immediately:
相關PDF資料 |
PDF描述 |
|---|---|
| MT90520AG | 8-Port Primary Rate Circuit Emulation AAL1 SAR |
| MT9072 | Ultraframer DS3/E3/DS2/E2/DS1/E1/DS0 |
| MT9072AB | Ultraframer DS3/E3/DS2/E2/DS1/E1/DS0 |
| MT9072AV | Ultraframer DS3/E3/DS2/E2/DS1/E1/DS0 |
| MT90820 | Large Digital Switch |
相關代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MT90520AG | 制造商:Microsemi Corporation 功能描述:ATM SAR 2.048MBPS 2.5V CBR 456BGA - Trays |
| MT90520AG2 | 制造商:Microsemi Corporation 功能描述:ATM SAR 2.048MBPS 2.5V CBR 456BGA - Trays 制造商:Zarlink Semiconductor Inc 功能描述:ATM SAR 2.048MBPS 2.5V CBR 456BGA - Trays |
| MT90528 | 制造商:ZARLINK 制造商全稱:Zarlink Semiconductor Inc 功能描述:28-Port Primary Rate Circuit Emulation AAL1 SAR |
| MT90528AG | 制造商:ZARLINK 制造商全稱:Zarlink Semiconductor Inc 功能描述:28-Port Primary Rate Circuit Emulation AAL1 SAR |
| MT90528AG2 | 制造商:ZARLINK 制造商全稱:Zarlink Semiconductor Inc 功能描述:28-Port Primary Rate Circuit Emulation AAL1 SAR |
發(fā)布緊急采購，3分鐘左右您將得到回復。